Laccase Mimics: Probing the Electrocatalytic Potential for CO₂ Reduction

Area of Science:

• Biocatalysis and Bioinorganic Chemistry
• Electrocatalysis and Sustainable Energy

Background:

• Laccase enzymes utilize copper redox centers for catalytic activity.
• Biogenic laccase mimics are explored for applications beyond traditional roles.
• Electrochemical CO₂ reduction (ECR) is a key area for sustainable energy research.

Purpose of the Study:

• To investigate the potential of laccase and copper-amino acid mimics in electrochemical CO₂ reduction (ECR).
• To evaluate the catalytic efficiency and selectivity of these mimics compared to native laccase.
• To demonstrate the application of laccase analogues as effective electrocatalysts.

Main Methods:

• Synthesis and characterization of copper-amino acid laccase mimics.
• Electrochemical evaluation of CO₂ reduction activity using the Cu²⁺/Cu¹⁺ redox system.
• Assessment of catalytic decolorization of azo and triphenylmethane dyes to confirm oxidative nature.

Main Results:

• Laccase mimics exhibited higher catalytic efficiencies than native laccase.
• Mimics demonstrated functional coherence through dye decolorization, indicating oxidative properties.
• The phenylalanine-copper (F-Cu) mimic achieved a high ECR yield rate of 35 ± 1.2 µmol cm⁻² mg⁻¹ h⁻¹, surpassing the enzyme's performance.

Conclusions:

• Copper-amino acid laccase mimics are promising electrocatalysts for ECR.
• The F-Cu mimic's performance is attributed to copper's inherent activity and amino acid ligand tuning.
• This research bridges biocatalysis and practical electrocatalysis for sustainable applications.